From: Sebastian Ene <redacted>

Allow direct messages to be forwarded from the host. The host should
not be sending framework messages so they are filtered out.

Signed-off-by: Sebastian Ene <redacted>
Reviewed-by: Yeoreum Yun <redacted>
Signed-off-by: Per Larsen <redacted>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 20 ++++++++++++++++++++
 include/linux/arm_ffa.h       |  3 +++
 2 files changed, 23 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index f731cc4c3f280a32acccca0de92b9ac6c8e05602..fc84595007f310004def7d525371fa7c128f244a 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c

@@ -862,6 +862,22 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
 	hyp_spin_unlock(&host_buffers.lock);
 }
 
+static void do_ffa_direct_msg(struct arm_smccc_1_2_regs *res,
+			      struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, flags, ctxt, 2);
+
+	struct arm_smccc_1_2_regs *args = (void *)&ctxt->regs.regs[0];
+
+	/* filter out framework messages and validate SBZ/MBZ bits */
+	if (flags) {
+		ffa_to_smccc_error(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	arm_smccc_1_2_smc(args, res);

diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 81e603839c4a51873090b7e22edbe7b33a7e94df..d209d0cdac1eb804be01e4607acac8f76cc99e40 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h

@@ -130,6 +130,9 @@
 #define FFA_FEAT_RXTX_MIN_SZ_16K	2
 #define FFA_FEAT_RXTX_MIN_SZ_MASK	GENMASK(1, 0)
 
+/* FFA message flags */
+#define FFA_MSG_FLAGS_MSG_TYPE		BIT(31)
+